2008 FEH AWD Traction Battery Discharge When Unused In Cold Weather
 

Hi -

I have a 2008 FEH AWD with 105K miles. I'm wondering how much discharge in the traction battery is "normal" in cold weather when I don't drive much.

I'm new to Portland, OR and in the 4 months that I've been here, my driving is usually just a 5 mile round trip twice a week. With the weather getting colder, I've had 2 or 3 occasions when my car has been sluggish with no battery assist as I start out on a trip after not having driven much. Today I had my EngineLink app running and noted that when I started out, the Traction Battery SOC was about 27% and Traction Battery Voltage was around 350V. By the end of the trip, the SOC was up to 53%. The 12V battery is 3 years old.

I don't have much to compare this to because prior to OR, I lived in Texas for 3 years where it was obviously much warmer and I drove at least 10 miles every 3 days. Prior to that, I lived in MD where I drove at least 25 miles a day, 5 days a week.

I'm going to be away for 16 days around the holiday. Should I be concerned about my car starting when I return?

Thanks!

Re: 2008 FEH AWD Traction Battery Discharge When Unused In Cold Weather
 

I can't speak to the FEH, but I can speak to NiMH chemistry.

SoC is an estimate. It's a complex algorithm that establishes upper and lower limit based on performance, and the numbers in between are only approximate.

You're not driving it enough. Period.

NiMH doesn't take charge well in cold weather, so the system protects the battery by using it very little and keeping charge/discharge currents pretty darn low. As the battery warms, it will begin to use it more.

If there's a way to force charge the battery with the engine, doing this periodically would help. I would certainly do it before you go on your trip.

Re: 2008 FEH AWD Traction Battery Discharge When Unused In Cold Weather
 

Thank you for that info.

I've searched but haven't seen anything about charging the FEH SOC beyond ~60%.

I think I'll start driving it more before I head out of town and look into getting a friend to drive it a few times while I'm away.

Thanks!

Re: 2008 FEH AWD Traction Battery Discharge When Unused In Cold Weather
 

Even 60% is better than nothing. I think your plan is a good one.

Re: 2008 FEH AWD Traction Battery Discharge When Unused In Cold Weather
 

I think Ford offered a battery heater option, but not sure for what years of FEH. Do a search here for battery heater.

Re: 2008 FEH AWD Traction Battery Discharge When Unused In Cold Weather
 

A common trick is to block the radiator to make the ICE warm up faster during cold weather. If you can park the Escape in heated garages of course that will help too.

Re: 2008 FEH AWD Traction Battery Discharge When Unused In Cold Weather
 

The FEH is designed to maintain a SOC around 53%. MG2 (via regenerative braking) will build SOC beyond this level but the vehicle will attempt to burn it off. This is all done in the name of durability.